1. Field of the Invention
This invention relates generally to method to defeat chemical warfare agents and other hazardous materials, and, more particularly, to a method and device for defeating bulk chemical warfare agents and other hazardous materials, such as those stored in a large drum or other container, by rendering them essentially useless and difficult to remove from a container.
2. Related Art
Chemical warfare agents and many toxic industrial chemicals (TICs), i.e., hazardous materials, that might be used as weapons are typically non-aqueous, i.e., organic compounds. In certain circumstances it may be desired to immobilize such materials in a container so that they can be safely transported or to defeat their use as weapons. In some situations, the container may be an integrated part of an industrial plant or it may be a stand-alone container, e.g., a drum, which cannot be safely opened except in a specially equipped hazardous material facility. In such circumstances, special means and steps must be taken so that the agents can be altered and rendered useless or neutralized.
Denying the utility of bulk or production quantities of chemical warfare agents and/or toxic industrial chemicals by a fast-acting, lightweight system for rendering the materials useless or undeliverable has generally used the approach of chemically neutralizing the agent or TIC. This may render the agent relatively safe to handle or dispose, but it usually requires a stoichiometric ratio of decontaminant or neutralizer to agent that is greater than one. For example, one or more decontaminant molecule is required to destroy or neutralize an agent molecule. Some types of decontamination have involved the use of absorbent materials. Some of these employ reactive chemical decontaminants to neutralize the agent. However, absorbent decontaminants in the prior art do not offer an efficient or low bulk means of immobilizing bulk agent.
Several thickeners have been used in the prior art for increasing the viscosity of chemicals for industrial purposes and for chemical warfare agents. Some are also used as absorbent barriers for protection from hazardous chemicals, which may include chemical agents. Such materials, however, are not readily dispersed within a container. Although they may absorb the agent, they do not generally imbibe the agent so that it is not readily released, for example by compression.
Cross-linked copolymers have been shown to be effective in the immobilization of hazardous materials by forming super-thickened gels or solid-like materials. However, the introduction of these materials into containers and their effective use to defeat bulk chemical agents without specific knowledge of the agent characteristics has not been previously addressed. Moreover, their direct use for the defeat of bulk quantities of already ‘thickened agent’ is not effective, because they cannot be readily dispersed.
Several means for breaching a closed container of hazardous material are known. These permit a tubulation or other hollow penetration of a container wall without the unwanted release of hazardous material from within the container. However, these devices do not allow for a simple and low cost means to insert material and mix it.
Although the chemical warfare agents of interest may span a multitude of variants such as organo-phosphorous compounds, which include G-type nerve agents and V-type nerve agents, and non-traditional agents, vesicants, blood agents, choking agents and/or incapacitating agents, a method is needed to render the targeted materials useless regardless of the type of chemical composition or chemical functionalities. To accomplish this objective, the method must be able to incapacitate the targeted materials without creating a new hazard in the process, either to personnel or the environment.
Several of the presently inventoried decontamination technologies are based on an aqueous decontaminant formulation, which may be fine for attacking lower, but still lethal concentrations or quantities of chemical warfare agents and rendering them useless. However, for dealing with bulk chemical warfare agents such as batch process preparations that may be stored in concentrated or ‘neat’ form and in quantities which comprise from one to hundreds of liters, these technologies are not viable solutions for a covert defeat. Part of the unsuitability of decontaminant to bulk agent defeat derives from unfavorable stoichiometric requirements. This is especially true for existing aqueous-based technologies, where extremely large quantities of decontamination materials may be required for bulk agent degradation. Also, a substantial amount of support equipment may be needed. Comparison can also be made to those processes that have been previously evaluated, and some employed, for destroying large caches of chemical agents as part of the stockpile and non-stockpile agent demilitarization programs. These processes include wet air oxidation, supercritical water oxidation, controlled hazardous material incinerations, and several others. All of these physical approaches require sophisticated equipment, substantial amounts of materials and/or energy, and are not particularly amenable to unattended operation.
A fast-acting, lightweight system that chemically attacks and neutralizes or destroys any chemical functionality of interest may be an insurmountable task because nearly all chemical warfare agents are organic molecules, which typically possess any of a myriad of different functionalities with significantly different reaction kinetics and susceptibilities to decontamination technology. An additional factor to consider entails the degree of sophistication in the preparation techniques and purity of the chemical agent of interest. Even though the known stockpiles of chemical agents are comprised primarily of ‘neat’ agents with added stabilizers, the clandestine compositions are expected to be less pure. Their manufacture will likely involve fewer expensive purification steps, and they may be stored in inert organic solvents as protection from unwanted aqueous degradation. A similar argument applies to several of the toxic industrial chemicals (TICs) that are identified as potential chemical weapons, such as those on government compiled lists such as the ITF-25 and ITF-40 lists, many of which are inorganic chemicals.